Capitol Hill employees staged a walkout Thursday in protest of recent grand jury decisions to not indict white police officers in the deaths of Michael Brown in Ferguson, Mo., and Eric Garner in New York City, both unarmed black men.

Senate chaplain Barry Black led the walkout, according to an NBC News report.

During the protest, staff members held up their hands in the "Don't Shoot" pose, relating to the Ferguson shooting of Brown by now-former officer Darren Wilson, which is a symbol used by protesters around the country.

Another phrase common among protesters nationwide is "I can't breathe," which were the last words spoken by Garner, whose cause of death was listed by the NYC medical examiner as having been caused by the chokehold he was put in during his arrest. The officer in that case was Officer Daniel Pantaleo.

More looting, 1 arrest as Bay Area protests dwindle

Police in Oakland, California, said demonstrators broke windows and looted stores and that there was one arrest for assaulting an officer in the latest U.S. protest over police violence.

Dozens of minority congressional staffers and Capitol employees have gathered to protest the killing of unarmed black men by police.

Dozens of minority congressional staffers and Capitol employees have gathered to protest the killing of unarmed black men by police.

Oakland and neighboring Berkeley have seen nightly demonstrations since the weekend in response to decisions by two grand juries not to charge white police officers in the killings of unarmed black men in Ferguson, Missouri, and New York City.

On Wednesday night, about 150 protesters, a smaller crowd than on previous evenings, left the campus of University of California-Berkeley and demonstrated without incident before marching south into Oakland, the city of Oakland said in a statement.

By that point, the protesters' numbers had dwindled to about 50 people, the statement said, some of whom broke windows at a T-Mobile store and a Chase bank. Looting also was reported in an area of small businesses at a downtown intersection, it said.

A Reuters photographer witnessed an undercover police officer, who had been marching with the demonstrators, pointing his pistol at protesters after he and his partner were attacked.

About 20 uniformed officers were quickly on the scene and detained one man. A spokesman for the Oakland Police Department said only that it had responded to a request for assistance "made by an outside agency," and referred all inquiries about the incident to the California Highway Patrol.

CHP media officials did not immediately respond to requests for comment.

The City of Oakland said in a statement one arrest was made overnight after an officer was assaulted, but it was not immediately clear whether that was the same incident witnessed by the Reuters photographer.

Two subway stations in downtown Oakland were shut down for a time late on Wednesday due to the protest, city officials said.

On previous evenings this week in the Bay Area, riot police have fired tear gas and pepper spray to disperse demonstrators, some of whom have thrown stones at the officers.

The protests are part of nationwide actions by activists amid turmoil over the policing of black communities.